Radius grinder for tools



Oct; 17, 1950 H. F. RYAN 2,526,57 P

RADIUS GRINDER FOR-'rooLs INVENTSR HowARo F. RYAN ATTORNEY och 17, 195o HF; RYANr 2,526,507

RADIUS GRINDERFOR Toons Filed Jan. 17, 1950 A3 Shets-Sheet 2 o 6 l G 8 o 9| 90 lOl if UIL i'ff//ff/myM-` @.glMmmm#mman/mm@ 35 W L /25 7 A l 77 85 g4 F'G7 l ma Il.

96 93 '9- r, I 83 7,7 74 73 l INVENTOR 95 94 9 l so, 6 HowARo r. RYAN f 79 E Il il BY ,fw 9| :u "99 l 82 'l 9 :l OO s; I 98- A W 2689 46 73 ATTORNEY Y OctQ 17,1950 H. F1 RYAN RADIUS vGRINDER FOR TOOLS Filed 4Jan. 17, 195o' I, Shets-Sheet 3 INVENTOR F. RYAN M KW HOWARD ATTORNEY Patented Oct. 1.7, 1950 *Unirse stares PATENT orties RADIUS GRINDER FOR TOOLS Howard F. Ryan, Long Beach, Calif.

Applicationlanuary 17, 1950, Serial No. 138,961

4 Claims.

This invention relates to a radius grinder for sharpening the teeth of rotary'cutters and the like.

One object of the invention is to provide a compact machine for sharpening rounded end cutter teeth. Another object is to pro-vide a lecision machine for sharpening rounded teeth on rotary cutters which machine is readily adjustable for diierent diameters and amount of relief and for different thicknesses of cutters.

These and other objects are attained by my invention which will be understood from the following description, reference being made to. the accompanying drawings in which: l

Figure 1 is a side elevational view of a preferred form of my radius grinder;`

Figure 2 is an end elevational view of the same;

Figure 3 is a fragmentary plan view of a typical cutter tooth showing its position relative to the grinding wheel;

Figure 4 is a diagrammatic view taken on the line 4 4 of Figure 3 showing the manner of rounding the outer cutting edge of a tooth, the cutter being shown in full lines at the start oi the operation and the broken lines sho-wing the finish of the operation;

Figure 5 is a diagrammatic view similar to Figure 4 showing a different position of a tooth and the grinder wheel giving a 180 rounded face;

Figure 6 is a cross-sectional view taken on the line 6 6 of Figure 1;

Figure 7 is a cross-sectional view taken on the line 1-1 of Figure 6;

Figure 8 is a front elevational view of the main Y frame;

Figure 9 is a front elevational View of the cutter-holding cradle mounted in the swing frame;

VFigure 10 is a front elevational View of the swing frame, the cutter-holding cradle having been removed;

Figure 11 is a plan View of the cutter-holding cradle;

Figure 12 is a plan View showing means for mounting a single cutter bar in a fixturev on.

the mandrel for grinding a rounded cutting end thereof;

Figure 13 is a side elevational view partly in section of the set-up of Figure 12; I

Figure 14 is a perspective View of the bar- `the indexing means and gauging means for use in sharpening the teeth of a rotary cutter; and

Figure'l is a perspective View showing a template or gauge used for positioning the tool.

In general, my machine consists of a, motor driven grinding wheel mounted to operate in a vertical plane on a horizontal axis, the peripheral face of the wheel being used for abrading, and a cutter-holding fixture mounted on a common base in yadjustable relation to the grinding wheel7 a U -shaped main frame having adjustable fastening means to hold it in operative relation to the grinding wheel, a swing frame pivotally mounted in the open end of the main frame, a, mandrelcarrying cradle pivotally attached to the swingv frame, the mandrel being ladjustable angularlyr means for turning the main frame on a central pivot so that the teethof the cutter are formed by the grinding wheel with a cylindrical or coni- Y cal cross-section.

holding fixture for the set-up of Figures 12 and Figure l5 is a fragmentary front View showing l The motor 2l having an elongated horizontal shaft 22 on which is mounted in the usual manner a grinding wheel 23 having a peripheral face 24 preferably not much wider than the peripheral length of a single tooth of the cutter to be sharpened, is mounted on a base plate 25.`` Mounting means for the tool holding and swing- Wheel Si attached at one end oi the block 26. The block 25 is provided witha movable top plate 32 to which is attached, on the underside, a

threaded follower 33 actuated by the screw 2Q; v

The movable top plate 32 is retained by the screws 34 and wear plate 39 to the lower dove-f tail slide block @Shaving the dovetail slide 3S whichis vadapted to slide in the corresponding dovetail groove'Si of the top plate 32, the adjustable wear plate 39 being provided on one side of the groove iiljbeing adjustable forwear on the surfaces by the set screws 3d in the holes 4i in the block 32;

unit 2&3, the screw 42 being actuated by the `Knob.

A4 and handwheel l5 on the protruding end of A The d-oveta-il slide unit i@ 26A is. similar to thev unit 2li and similar parts f.

the cross-feed screw 452.

A cross-feed screw 52 and fol- Ylower 43 .are pro-vided to give relative sliding 2 movement between the upper portion 32A of e.' slide unit 26A and upper block 32 ci the slide r are marked with a suix A The main frame base block l5 is arranged for pivotal connection to the upper dove-tail slide block 32A by the threaded stud il which extends through the index disk 58 attached to the base block 46, and into a circular recess 49 in the main frame base block 45. The stud All' is provided with a tapered recess, and is held in the recess 49 by the wedge set screw 59 and the wedge pin 5|, which permits the turning in a horizontal plane on the main frame base block l5 relative to the upper dovetail slide block 32A. The main frame 52 is mounted at the ends of the base block 45 by the pivot screws the inclination from the vertical of the main frame 52 being adjustably fixed by the horizontal abutting screw 55, which is threadedly mounted in the post 55 on the base plate 25, an end adjusting knob 5`| and a lock nut 58 being provided. A nat spring 59 attached at one end to the base block 95, and pressing at its other end against the ribbed back plate 60 of the frame 52 tends to hold the frame against the end of the abutting screw 55.

The U-shaped swing frame 6| is pivotally mounted at the upper ends of the main frame 52, on the inside (adjacent the motor) by the pivot screw 82, and at the opposite side on the turning shaft 63 which is fixed in the hole 64 in the outside leg 55 of the main frame 52 by the set screw 65A. The turning shaft 63 is extended outwardly to receive the turning handle 65 and the stop block 67, whose end stop screws 68 and 59 are adapted to limit the turning motion of the shaft 55 by abutting the edges of the outside leg 65 of the main frame E2. The vertical position of the axis on which the swinging frame 6| turns is indicated by inwardly extending pins 'i9 having axial lands in a plane at right angles to the axis of the mandrel 12. Removable templates or gauges G (Figure 16) may be placed on these lands in the operation of adjusting the mandrel for grinding a particular cutter, to indicate the axis of turning and therefore the axis f the cylindrical or conical surface to be ground on the tooth or tool.

The mandrel 'i2 which is adapted to receive the center opening of a toothed cutter or the fixture F for bar tools, is threadedly attached on the threaded pin 'M which is rigidly attached to the movable plate T of the cradle 'I3 by the nut 75 on the extended threaded end 16. The cutter C is held on the mandrel 12 by the recessed nger nut |04. The movable plate is longitudinally positioned in the cradle '|3 by the knurled indexed knob 'I8 which is attached to one end of a traverse screw '|9 mounted in a recess 80 in the cradle |3, the other end of the traverse screw engaging a threaded hole 8| in the movable plate the movement of the plate being guided by the dovetail groove 82 in the cradle 'I3 complementary to thedovetail follower 83 extending from the movable plate 71. Any wear in this sliding arrangement is compensated by the wear plate 84 arranged along one side of the groove S2, with adjusting set screws 85 arranged to be accessible from the edge of the cradle. The cradle 73 is adapted to be pivotally mounted on its edge members 85 by the pivot screws B'l and 88 extending from the swing frame 6| at intermediate positions along the legs thereof, the angular position of the cradle 'I3 relative to the swing frame being regulated and adjusted by telescoping pivoted screw means as described below, this adjustment providing quick and accurate means for changing the position of 'the mandrel 12 to accommodate cutters or tools of different thicknesses.

The swing frame 6| is provided at its lower or non-pivoted end with a bridge plate 89 which is laterally displaced and overlays the nonpiVoted end portion of the cradle 13. The cradle 13 and the swing frame 6| are adjustably angularly positioned by coupling means consisting of a telescoping adjusting screw set which is doubly pivoted so that the positioning or" the mandrel '|2 relative to its distance from the axis of swing is not appreciably disturbed by the adjustment of the angular relation between the cradle and the swinging frame. A collar is mounted on the bridge plate 89, to the inside 0I" which is pivoted, parallel to the axis of swing, a threaded sleeve 9|, the pivot screws 92 and 93 extending through the collar 99 to engage conical holes in the outer periphery of the sleeve 9|, approximately midway between the ends. The hollow outer screw 94, provided with a thumb knob 95 is threaded on the outside with threads to t the threads on the inside of the sleeve 9|. A lock nut 96 is provided on the screw 963. The inner screw 97 is threaded to fit the inside threads of the hollow screw 95, to form a doubleacting telescoping screw set. The free end 98 of the inner screw 9'1 is pivotally mounted in the bearing lugs 99 and |09 which are provided on the fixed portion of the cradle 13, disposed beneath the bridge plate 89, the axis of the pivoting pin |9| being parallel to the axis of the pivot mounting of the sleeve 9| in the collar 98.

The use of my radius grinder for sharpening teeth of rotary cutters will be readily understood from the above description of its structural arrangement. The cutter C whose teeth T are to be sharpened to a radius, is mounted on the mandrel T2 and heldY in place by the recessed mandrel nut. |94. The median plane of the cutter is then aligned with the axis of the indicating pins 'IIJ by adjusting the angular relation between the cradle i3 and the swing frame 6| by means of the knob 95 on the screw 94; the axis of the mandrel being adjusted toward or away from the axis of swing by means of the index knob 18. The radius of the cut is determined by the spacing of the main frame 52 from the cutting surface of the wheel by means of the screw 55, as indicated in Figures 4 and 5. The curved surface of each tooth may be cylindrical and tangent to the periphery of the cutter, or it may be conical, thereby giving a relief area back of the cutting edge, this being determined by the angular position of the main frame as indicated by the indexing means 48.

A flat indexing spring |53 may be arranged in the slot |52 in the pivoted end of the swing frame 6| as indicated in Figure l5, to position each g tooth for the grinding operation.

My radius grinder may also be used for grinding individual bar critters as indicated in Figures 12, 13 and 14. A xture F is provided to fit on the stud i4 with a clamp-ing nut i 95A and washer |95 arranged to hold the tool steel :bars B in the groove of the fixture. The end of the bar B may then be rounded in the manner described for rounding teeth or rotary cutters.

The advantages of my grinding machine will be apparent. The several adjustment means permit a large variation in the contours of the rounded cutter tooth which may be formed or sharpened on the machine. Having once adjusted the machine, the teeth of each cutter may be v:formed uniformly and with great precision. The

vertical; adjusting means for positioning said main frame relative to the grinding wheel surface; a swing frame pivotally mounted on the upper ends of said upright arms of said main frame; a cradle pivotally mounted in said swing frame at points intermediate the ends of said cradle and said arms; a mandrel mounted on said cradle, said mandrel being adapted for holding said cutters during grinding; coupling means for adjustably positioning said cradle on its pivots relative to the said swing frame; and handle means for turning said swing frame through a portion of a revolution while contacting said cutter against said grinding wheel, said cutter being mounted on said mandrel.

2. In a radius grinder having a base upon which is xedly mounted a peripheral grinding wheel with motor means therefor, a iixture for holding a cutter against said grinding wheel attached on said grinder base comprising a main frame having upright arms adapted to be inclined from the vertical; adjusting means for positioning said main frame relative to the grinding wheel surface; a swing frame pivotally mounted on the upper ends of said upright arms of said main frame; a cradle pivotally mounted on said swing frame at points intermediate the ends of said cradle and said arms; a mandrel mounted on said cradle, said mandrel being adapted for holding said cutter during grinding; slide means for moving said mandrel toward and away from the pivot axis of turning of said swing frame; coupling means for adjustably positioning said cradle on its pivots relative to said swing frame; and handle means for turning said swing frame through a portion of a revolution while contacting a cutter against said grinding wheel, said cutter being mounted on said mandrel. y

3. In a radius grinder for cutter teeth and the like having a base upon which is xedly mounted a peripheral grinding wheel with motor means therefor, a xture for holding a toothed cutter against said grinding wheel, said fixture being pivotally on cross slide means attached on said grinder base, said xture comprising a main frame having upright arms adapted to be inclined from the vertical; adjusting means for positioning said main frame relative to the grinding wheel surface; a swing frame pivotally mounted on the upper ends of said upright arms of said main frame; a cradle pivotally mounted in said swing frame at points intermediate the ends of said cradle and said arms; a mandrel vertically mounted on said cradle, said mandrel being adapted for holding said cutter during grinding; slide means for moving said mandrel toward and away from the pivot axis of turning of said swing frame; coupling means for adjustably positioning said cradle on its pivots relative to the said swing frame; and handle means for turning said swing frame through a portion of a revolution while contacting a selected tooth of said cutter against said grinding wheel, said cutter being mounted on said mandrel.

4. The fixture as described in claim 2 in which the coupling means between said cradle and said swing frame comprises telescoping screws which are pivotally connected respectively to said cradle and said swing frame, the axis of said pivotal connections being parallel to the axis of swinging of said swing frame.

HOWARD F. RYAN.

No references cited. 

